This invention generally relates to reclosable packaging for containing powder or other granular or particulate matter. More particularly, it relates to reclosable packages for containing powder that are gusseted.
In the use of plastic bags, pouches and other packages, particularly for containing foodstuffs, it is important that the bag be hermetically sealed until the purchaser acquires the bag and its contents, takes them home, and opens the bag or package for the first time. It is then commercially attractive and useful for the consumer that the bag or package be reclosable so that its contents may be protected. Flexible plastic zippers have proven to be excellent for reclosable bags, because they may be manufactured with high-speed equipment and are reliable for repeated reuse.
A typical zipper has a pair of opposing zipper portions formed by extrusion. The zipper portions are extruded with respective interlockable profiles that can be interlocked when opposing sides of the mouth of the bag are pressed together. The profiles in plastic zippers can take on various well-known configurations, e.g. interlocking ribs and grooves, interlocking elements having so-called male and female profiles, interlocking alternating hook-shaped closure elements, etc. In the last case, there may be no difference in appearance between the opposing closure elements. The zipper portions are joined in some manner to the material from which the bags themselves are manufactured. Sometimes the zipper portions are provided with respective extension flanges to which the uppermost portions of the front and rear walls of the bag are joined. In addition, the zipper portions may be provided with pull flanges, which are gripped by the user to pull open the zipper.
Although flexible zippers of this variety are quite popular, they do not always prevent the inadvertent or unwelcome opening of a bag or package within the store; and various additions have been made to provide tamper-evident seals that would reveal when it has been opened prior to purchase. It is known to provide a zipper package construction that is designed to undergo some permanent change in the package appearance when the package is opened for the first time. In particular, it is known to provide a zipper package with a tamper-evident, non-reclosable peel seal that gives a positive indication of having been broken when a package is first opened.
Such zipper package constructions should also have other desirable features. For example, the package should be “user friendly” in the sense that the steps necessary for the initial opening of the package prior to the use of the zipper are obvious or intuitive to the consumer and easy to perform. Also the zipper package design should allow the package to be formed on conventional packaging equipment with little or no modification of the equipment being required. In cases where the package contents require hermetic sealing, it is desirable that the tamper-evident feature also permit such hermetic sealing.
There is a need for a reclosable package suitable for containing scoopable powdery products such as flour and detergent. Such a package should have a zippered mouth configured and disposed so that insertion of a scoop into the package is facilitated. The package should also include a hermetic seal and an easy-open feature